Some related-art gas meters that measure the quantity of consumed gas have a safety function for cutting off a gas supply channel, and the like, when a problem has arisen during usage of a gas. The safety functions include a function for cutting off a gas supply channel by means of a shutoff valve when, for instance, a seismoscope detects a predetermined seismic intensity level or more; or for cutting off the gas supply channel when a predetermined flow or a predetermined operating time is exceeded.
Patent Document 1 shows a gas meter control system that stops a gas supply by use of a communication line for automatic reading or a prepaid card system when a quantity of available gas is achieved, in order to supply the quantity of gas commensurate with a payment. Patent Document 2 discloses a network system that automatically reads the quantity of consumed water, electricity, gas, and the like, and that enables calculation and charging of a bill, checking of a water leak, transfer of information about detection of an electricity leak and a gas leak, and the like. Patent Document 3 discloses a gas management system that shuts off a gas supply at a point in time when remaining balance information about a gas bill has come to zero as a result of use of a prepaid card, thereby streamlining a meter reading service and a bill collection service.
Patent Document 1: JP-A-8-5398
Patent Document 2: JP-A-2005-18720
Patent Document 3: JP-A-2002-74497